The present invention relates to a video processing apparatus such as a television receiver and, more particularly, to a video processing apparatus and a video processing method for forming a video signal being capable of displaying a main screen and a sub-screen in one screen at once.
Of conventional television receivers, various television receivers each or which can achieve a two-screen display which allows a main screen and a sub-screen to be displayed at once as a display mode are merchandized. FIGS. 3A to 3C show examples of the two-screen display. As shown in FIG. 3A, a main screen 1a is displayed on the left in a display screen 1, and a sub-screen 1b is displayed on the right to have the same size as that of the main screen. In another example, for example, as shown in FIG. 3B, a main screen 2a is displayed on a left large part of a display screen 2, and a small sub-screen 2b is displayed at the lower right corner. In still another example, for example, as shown in FIG. 3C, a main screen is displayed on a display screen 3 as a full screen, and a small sub-screen 3a may be displayed to partially overlap the main screen. Although the two-screen displays have been described above, some television receiver can achieve a multi-screen display which allows two or more sub-screens (i.e., a total of three or more screens) to be displayed at once.
In the example shown in FIG. 3A, although the main screen 1a and the sub-screen 1b are equal to each other in size, with respect to sound, only an audio signal added to a video signal of the main screen 1a is generally reproduced. However, one of the left and right screens is determined as a main screen depending on a set state at this time.
In this case, in some television receiver which can achieve a recent two-screen display (or a multi-screen display having two or more screens), two tuners for receiving television broadcast signals are prepared such that a main screen and a sub-screen independently perform channel switching operations, one tuner performs reception for the main screen, and the other tuner performs reception for the sub-screen. In this television receiver having the two tuners arranged therein, a user can basically realize a desired arbitrary combination as a main screen and a sub-screen. In a television receiver in which one tuner for receiving signals having the same forms is prepared to achieve a two-screen display, different input video images can be selected on the main screen and the sub-screen. More specifically, for example, a video image obtained by a television broadcast of a ground wave is displayed on the main screen, and a video image of a different system such as a video image obtained by a television broadcast of a satellite broadcast wave or an external input is displayed on the sub-screen.
In a television receiver which achieves the two-screen display described above, even if two tuners are prepared, the video image of the same channel is prohibited from being displayed on the main screen and the sub-screen at once. This is because the image qualities of the main screen and the sub-screen are different from each other.
More specifically, for a tuner or a video signal processing circuit for receiving a signal constituting a main screen, a high-grade circuit component which can display an image having relatively high quality is generally used. However, for a tuner or a video signal processing circuit for receiving a signal constituting a sub-screen, a circuit component for processing an image having an image quality poorer than that of the image of the main screen is used. Therefore, when the same image is displayed on the main screen and the sub-screen, although the image on the main screen is basically the same as that on the sub-screen, the image qualities of these images are different from each other, and unnatural display forms are established. In particular, as shown in FIG. 3A, when a display mode in which the main screen and the sub-screen are equal to each other in size is established, the difference between the image qualities is conspicuous. Especially, in a recent television receiver, a circuit for processing a video signal for a main screen is designed to perform a complex process of improving image quality by a digital process, image qualities are considerably different from each other.
In addition, even if a tuner or a video signal processing circuit for a main screen and a tuner or a video image processing circuit for a sub-screen are constituted by components having the same configurations, the main screen and the sub-screen are generally different from each other in image quality depending on a set state of the respective circuits. It is very difficult to make the image qualities of the images equal to each other. Even if the process for the main screen and the process for the sub-screen have the same configurations, the video image of the same channel is prohibited from being displayed on the main screen and the sub-screen at once.
However, when the video image of the same channel or the same input is prohibited from being displayed on a main screen and a sub-screen, operability viewed from an operator who operates a television receiver is disadvantageously unnatural. More specifically, for example, when a specific channel (e.g., channel number 3) of a television broadcast of a ground wave is displayed on the main screen, and a television broadcast of a ground wave is also displayed on the sub-screen, a channel switching operation of the sub-screen is performed to sequentially switch channel number to 1, 2, . . . , after the image of channel 2 is displayed, the image of channel 3 displayed on the main screen is skipped, and the image of channel 4 is displayed. Therefore, in an ordinary channel switching operation (switching operation when a two-screen display is not established), when a channel switching operation is performed from channel 1 in an ascending order, and a channel-up key is pressed three times, the image of channel 4 is displayed, while in a channel switching operation of the sub-screen, when a channel-up key is pressed three times, the image of channel 5 is displayed on the sub-screen. For this reason, the operability of the channel switching operation when the two-screen display is not established is different from the operability of the channel switching operation when the two-screen display is established, which confuses a user.
Although the problem which is posed when a two-screen display is performed by a television receiver has been described, the same problem as described above is posed in another video device for performing video signal processing for a two-screen display or a multi-screen display. More specifically, for example, in a video tape recording/reproducing device (so-called VTR device), two video signals selected by the device are used to form video signals for performing a two-screen display, and a two-screen display can be performed on a television receiver for image-receiving the video signals output from the device. In this case, for the reason described above, the video signals output from the recording/reproducing device are limited such that the main screen and the sub-screen do not have the same contents.
The present invention has been made in consideration of the problems, and has its object to improve operability when a two-screen display or a multi-screen display having two or more screens is performed.
The first aspect of the present invention provides a video processing apparatus including: selection means for selecting a video signal constituting a main screen from a plurality of video signals and selecting a video signal constituting a sub-screen from the plurality of video signals; first video processing means for processing the video signal for the main screen selected by the selection means; second video processing means for processing the video signal for the sub-screen selected by the selection means; synthesizing means for setting a video signal obtained when the main screen and the sub-screen are synthesized in one screen by using the video signal processed by the first video processing means and the video signal processed by the second video processing means; and control means for, when the video signal for the main screen selected by the selection means and the video signal for the sub-screen selected by the selection means are the same video signals, performing control for setting a video signal obtained when the main screen and the sub-screen are synthesized in one screen by using only the video signal processed by the first video processing means in the synthesizing means.
According to the first aspect, when the main screen and the sub-screen are constituted by the same video signals, the main screen and the sub-screen are constituted by the video signals processed by the same circuit system, and the image qualities of the main screen and the sub-screen are not different from each other. Therefore, video images having the same contents need not be prohibited from being displayed on the main screen and the sub-screen. when an operation such as channel switching or input selection is performed, operability obtained when a two-screen display or a multi-screen display is performed and operability obtained when only an ordinary main screen is displayed can be set to be the same operability, the operability of channel switching or input selection does not change depending on display modes, and preferable operability is assured.
The second aspect of the present invention provides a video processing apparatus, in the first aspect, including display means for image-receiving the video signal synthesized by the synthesizing means.
According to the second aspect, operability in an image receiver which can achieve a two-screen display or a multi-screen display can be improved.
The third aspect of the present invention provides a video processing apparatus, in the first aspect, including a video signal output terminal for outputting the video signal synthesized by the synthesizing means.
According to the third aspect, operability in various video devices such as a video tape recording/reproducing device which can output a video signal which can achieve a two-screen display or a multi-screen display can be improved.
The fourth aspect of the present invention provides a video processing apparatus wherein, in the first aspect, the main screen and the sub-screen obtained by the image signal synthesized by the synthesizing means are screens which are almost equal to each other in size.
According to the fourth aspect, when a video signal which displays the main screen and the sub-screen to have almost equal sizes is set, image qualities obtained when the same video images are displayed can be made equal to each other.
The fifth aspect of the present invention provides a video processing apparatus wherein, in the first aspect, the main screen and the sub-screen obtained by the video signal synthesized by the synthesizing means are designed such that the sub-screen is smaller than the main screen in size.
According to the fifth aspect, when the video signal which displays the main screen and the sub-screen in different sizes is set, image qualities obtained the same video images are displayed can be made equal to each other.
The sixth aspect of the present invention provides a video processing apparatus wherein, in the fifth aspect, the sub-screen is displayed in a region which is a part of the main screen.
According to the sixth aspect, when a video signal which displays the sub-screen by using the region which is the part of the main screen is set, image qualities obtained when the same video images are displayed can be made equal to each other.
The seventh aspect of the present invention provides a video processing method including the steps of: selecting a video signal constituting a main screen from a plurality of video signals and selecting a video signal constituting a sub-screen from the plurality of video signals; setting a video signal obtained when the main screen and the sub-screen are synthesized in one screen after video processing operations are independently performed to the selected video signals, respectively; and, when the video signal for the main screen and the video signal for the sub-screen are the same video signals, setting a video signal obtained when the main screen and the sub-screen are synthesized in one screen by using only the video signal subjected to the video processing operation for the main screen or the video signal subjected to the video processing operation for the sub-screen.
When the processing method according to the seventh aspect is applied, when the main screen and the sub-screen are constituted by the same video signals, the main screen and the sub-screen are constituted by video signals processed by the same circuit system, and the image qualities of the main screen and the sub-screen are not different from each other. Therefore, video images having the same contents need not be prohibited from being displayed on the main screen and the sub-screen. When an operation such as channel switching or input selection is performed, operability obtained when a two-screen display or a multi-screen display is performed and operability obtained when only an ordinary main screen is displayed can be set to be the same operability, the operability of channel switching or input selection does not change depending on display modes, and preferable operability is assured.
The eighth aspect of the present invention provides a video processing method wherein, in the seventh aspect, a video signal obtained when the main screen and the sub-screen are synthesized is displayed.
According to the eighth aspect, operability obtained when a two-screen display or a multi-screen display is performed can be improved.
The ninth aspect of the present invention provides a video processing method, in the seventh aspect, a video signal obtained when the main screen and the sub-screen are synthesized is output.
According to the ninth aspect, operability in an output device when a video signal which can achieve a two-screen display or a multi-screen display is output can be improved.
The tenth aspect of the present invention provides a video processing method wherein, in the seventh aspect, the main screen and the sub-screen which are synthesized are screens which are almost equal to each other in size.
According to the tenth aspect, when the main screen and the sub-screen are displayed to have almost equal sizes, image qualities obtained when the same video images are displayed can be made equal to each other.
The eleventh aspect of the present invention provides a video processing method wherein, in the seventh aspect, the main screen and the sub-screen which are synthesized are designed such that the sub-screen is smaller than the main screen in size.
According to the eleventh aspect, when the main screen and the sub-screen are displayed in different sizes, image qualities obtained the same video images are displayed can be made equal to each other.
The twelfth aspect of the present invention provides a video processing method wherein, in the eleventh aspect, the sub-screen is displayed in a region which is a part of the main screen.
According to the twelfth aspect, when the sub-screen is displayed by using the region which is the part of the main screen, image qualities obtained when the same video images are displayed can be made equal to each other.